The invention relates to a method for the closed-loop knock control of an internal combustion engine. A method for closed loop knock control is known in which--when one cylinder knocks an ignition angle retardation of at least this cylinder and then a resetting of the ignition angle is effected.
In the operation of an internal combustion engine, so-called "knocking" represents a critical operating condition which has an extremely unfavorable effect on the life of the internal combustion engine. A so-called closed-loop knock control which shifts the ignition angle in the "retarded" direction when a cylinder of the internal combustion engine knocks is known. This shift of the ignition angle allows knocking to be eliminated. After a certain time, controlled resetting to the original ignition angle, which is, for example, stored in a map, is effected. The controlled resetting is preferably carried out in steps until the controlled map angle is reached. If the cylinder knocks again, the process is repeated. The resetting is not carried out as far as the controlled map angle if knocking has already occurred previously. A retardation is then performed again starting from the current ignition angle.
A so-called adaptive closed-loop knock control is also known, in which the ignition angle at which the associated cylinder knocks with a permissible knocking intensity is stored. This ignition angle is used in subsequent control operations instead of an ignition angle stored in a map.
In turbocharged engines, ignition angle retardation is problematic because this leads to an increase in the exhaust gas temperature and thus to a possibly impermissible thermal loading of the turbine of the turbocharger.